A low-cost electric-field energy harvester for an MV/HV asset-monitoring smart-sensor

This paper investigates the powering of smart-grid-sensors with electric fields (E-fields) present in abundance near most medium-to-high voltage (MV/HV) utility assets. A unique E-field energy harvester is proposed which is integrated into a sensor's enclosure, thereby ensuring low-cost and compact size. The proposed energy harvester can be used with multiple assets by virtue of its shape which also allows installation without interruption of the MV/HV asset. Design methodology of the harvester through Maxwell simulations along with a new and efficient circuit design for obtaining a regulated DC supply is presented. A medium voltage prototype of the proposed E-field energy harvester integrated with a wireless voltage sensor is built and tested on a 35 kV bus. The prototype provides 17 mW of continuous power at 35 kV with a high energy density. This power is enough to operate a low-duty cycle sensor node stuck-on to an MV/HV asset. The prototype shows promising results and demonstrates the efficacy of using E-fields for powering smart grid sensors for MV/HV assets.